U.S. patent application number 13/573756 was filed with the patent office on 2013-10-24 for implantable bone support systems.
This patent application is currently assigned to Osteosymbionics, LLC. The applicant listed for this patent is Osteosymbionics, LLC. Invention is credited to Cynthia M. Brogan, Carl Michael Nilsson.
Application Number | 20130282011 13/573756 |
Document ID | / |
Family ID | 49380815 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130282011 |
Kind Code |
A1 |
Brogan; Cynthia M. ; et
al. |
October 24, 2013 |
Implantable bone support systems
Abstract
An implantable bone support system including a shelf clip
supported on a portion of the perimeter of the skull opening. The
shelf clip includes upper and lower body portions. The legs of the
lower body portion are positioned such that one leg is engaged with
the skull perimeter in a direction away from the skull opening. The
opposing leg is positioned into the skull opening to form a portion
of a shelf for receiving the bone flap or implant. In an adjustable
height embodiment, the ratcheting leg of the upper body portion
engages a central post, via ratchet teeth on the leg and the
central post, and is pressed into engagement to capture the skull
between the upper and lower body portions. The removable or locking
leg is formed for engagement with the upper body portion of the
clip, and engages an external surface of the bone flap or implant
to capture the bone flap or implant within the shelf created by the
clips within the skull opening.
Inventors: |
Brogan; Cynthia M.;
(Cleveland Hts., OH) ; Nilsson; Carl Michael;
(Moreland Hills, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Osteosymbionics, LLC; |
|
|
US |
|
|
Assignee: |
Osteosymbionics, LLC
Cleveland
OH
|
Family ID: |
49380815 |
Appl. No.: |
13/573756 |
Filed: |
October 3, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61624281 |
Apr 14, 2012 |
|
|
|
61542386 |
Oct 3, 2011 |
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Current U.S.
Class: |
606/75 ;
606/86R |
Current CPC
Class: |
A61B 2090/037 20160201;
A61B 17/8872 20130101; A61B 17/8863 20130101; A61B 17/8869
20130101; A61B 17/688 20130101 |
Class at
Publication: |
606/75 ;
606/86.R |
International
Class: |
A61B 17/68 20060101
A61B017/68; A61B 17/88 20060101 A61B017/88 |
Claims
1. An implantable bone support system forming a shelf to locate,
stabilize and retain a bony structure within a patient, and thereby
supports bone in-growth during the healing process to allow bone
formation across the kerf/gap.
2. The system of claim 1 which is placed without the use of
external fasteners, such as screw, pins, etc.
3. The system of claim 1 which is placed and removed without the
use of any standard surgical equipment or instrumentation.
4. A support shelf or ledge for supporting a bone flap within a
skull opening comprising a clip having at least 3 barbed legs
positioned in at least 3 locations surrounding the perimeter of the
skull opening.
5. A temporary fixation device for positioning together pieces of
bone and/or implant materials for later reconstructive placement
comprising a clip positioned to surround a portion of a perimeter
of the pieces of bone and/or implant material and for engagement of
adjacent pieces of the surrounded pieces of bone and/or implant
material.
6. The system of claim 1 comprising a clip having at least 3 legs
having sharp points extending from the legs to secure the leg in
engaged position with the adjacent bone, and 2 of the legs are
engaged on an under side of the skull and bone flap.
7. The clip of claims 4 and 6 comprising an additional leg or plate
extending from the clip for capturing the bone flap upon engagement
with an external surface of the bone flap.
8. The clip of claim 7, wherein 2 of the legs extend from a lower
body portion of the clip, and one leg or plate extends from an
upper body portion of the clip and wherein the upper and lower body
portions are interconnected by a central post having ratchet teeth
for engagement with the plate and ratcheting engagement of the
central post and plate into engagement with the bone flap.
9. A bone support clip insertion tool having two handles
interconnected at a hinge, where movement of the interconnected
handles drives a plunger to engage a locking leg member with a bone
support clip.
Description
PRIORITY CLAIM
[0001] This application claims priority from pending provisional
patent applications, Ser. Nos. 61/624,281 filed Apr. 14, 2012 and
61/542,386 filed Oct. 3, 2011, the subject matters of which are
incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The present application is for an implantable bone support
system, and more specifically for implanted devices or clips for
stabilizing and supporting bone segments or custom-shaped implants
within a skull opening.
BACKGROUND
[0003] A craniotomy is a surgical operation in which a bone flap is
removed from the skull to access the brain. Craniotomies are often
a critical operation performed on patients suffering from brain
lesions or traumatic brain injury. Such surgical procedures are
also conducted to allow doctors to surgically implant deep brain
stimulators for the treatment of Parkinson's disease, epilepsy and
cerebellar tremor. The location and amount of skull that needs to
be removed depends to a large extent on the type of surgery being
performed. In a craniotomy, the bone is replaced after access to
the brain is completed.
[0004] To remove the bone flap, one common surgical practice is to
drill 3 holes in a triangular pattern, and saw between the holes to
form a triangular bone flap which is then removed to access the
brain cavity. Alternatively, 4 holes may be drilled with the saw
cuts forming a rectangle. More holes are possible depending on
anatomy and the surgeon.
[0005] Following the performance of the necessary medical
procedures, the bone flap must be replaced within the skull
opening. Due to the use of a cutting tool the bone flap will be
slightly smaller than the skull opening. A gap, formed between the
skull opening and bone flap due to the kerf of the bone cutting
instrument, is typically between 1 and up to 3 mm. In the past,
fixation of the bone flap to the skull has been accomplished using
a variety of methods and devices, but commonly, plates and bone
screws are used to bridge and stabilize, respectively, the spaced
apart bone segments. To secure the plates to each bone surface, at
least 2 screws are used on each side of each plate (depending on
plate geometry it can be either 1 or 2 screws, though 2 screws is
more customary). Since the preferred technique uses 3 plates to
fully stabilize the bone segments and ensure a strong attachment,
this results in the use of up to twelve screws. The use of such a
large number of screws requires the time consuming process of
placing the screw includes potentially pre-drilling and tapping the
holes and then inserting the screws, all conducted towards the end
of the surgical procedure, thereby increasing the total surgery
time.
[0006] Another bone flap replacement technique attempts to abut the
bone flap against the skull opening to obtain a large surface of
bone to bone contact in order to encourage bone growth across the
two meeting bone segments, while securing the remaining portion of
the perimeter opening with mortar and plates/screws. Such attempts
have not been entirely successful, as the joint is brittle and the
bone flap may not remain in position and that due to the kerf, the
distance between the bone segments is now twice as big on the
opposing side. In such applications, the bone flap is merely held
in place, as the gap is not filled. Additionally, in the event it
is desired that the bone screws and plates are flush with the
skull, in order to avoid adhesions where the tissue and scalp
contact the screws, further time consuming bone removal may be
required. Still further, such attachment methods do not enable the
ready removal of the screws to again remove the bone flap to
reaccess the brain cavity in the event further surgery and surgical
procedures are required. As a result, additional bone removal may
be required to remove the bone screws in the event that cannot be
unscrewed.
[0007] An additional prior art method for repositioning the bone
flap which does fill the gap is a Cranial LOOP.TM. device
manufactured by NEOS Surgery S.L. of Barcelona, Spain, as disclosed
in U.S. Patent Application Pub. No. 2008/0051792. This type of
device is positioned within the gap between the bone flap and skull
and acts like a grommet to sandwich the bone flap, but does not
support or carry the weight of the bone flap. Additional devices
along these lines are also shown in U.S. Pat. No. 6,022,351 to
Bremer and U.S. Pat. No. 6,379,363 to Herrington, for example.
SUMMARY
[0008] The present application provides an improved implantable
bone support system which solves numerous problems. The present
system may be used in connection with kerf or gap filling
situations or no kerf trauma applications, as well as for placing
PMMA, PEEK, titanium or ceramic implants. The bone support system
includes a titanium shelf clip which may be attached alone or at
numerous positions surrounding the perimeter of the opening formed
in the skull. The shelf clips support the bone flap or implant
within the skull opening and prevent it from entering the brain
cavity. The use of at least 2-3 shelf clips forms an interior shelf
for supporting and engaging the bone flap or implant which may then
be further secured. While at least 3 shelf clips may be preferred
to provide a fully supported interior shelf for the bone flap or
implant, more clips may be used as needed for additional
support.
[0009] The bone support system provides a simple, fast and easy
method and device for supporting the bone flap or implant and
eliminates the need for the time consuming use of screws. As a
result, surgical time to install the bone support system is
reduced. Additionally, the shelf clips have a smooth and low
profile which avoid adhesions and engagement issues between the
skull and the scalp tissue. Still further, the shelf clips may be
readily removed in the event further surgery is required to remove
the bone flap and re-access the brain cavity.
[0010] The shelf clip of the implantable bone support system
includes a lower body portion having a base and opposing barbed
legs extending from the base for engagement with the skull and with
the bone flap. The base also supports a central post, supporting an
upper engagement portion having a locking leg for engagement with
the skull and a removable leg for engagement with the bone flap or
implant. The leg which engages the bone flap or implant may be of a
variety of sizes and shapes, but may also itself be large enough to
serve as a cover over the skull opening. In one embodiment, the
central post is provided as two posts having ratchet teeth for
ratcheting engagement with the upper engagement portion. The clip
components may be stamped metal members or injection molded parts,
which may be formed of numerous well known long term biocompatible
implant materials, such as stainless steel, titanium or PEEK.
[0011] The shelf clip is supported on a portion of the perimeter of
the skull opening. The legs of the lower body portion are
positioned such that one leg is engaged with the perimeter in a
direction away from the skull opening. The opposing leg is
positioned into the skull opening to form a portion of the shelf
for receiving the bone flap. The locking leg of the upper body
portion engages the central post, via ratchet teeth on the locking
leg and the central post, and is pressed into engagement to capture
the skull between the upper and lower body portions. The removable
leg is formed for engagement with the upper body portion of the
clip, and engages an external surface of the bone flap or implant
to capture the bone flap or implant within the shelf created by the
clips within the skull opening. The clips are held in place by
retention barbs or holes formed in each leg, since each clip must
be held in position on the skull without manual assistance, screws
or suturing when the bone flap is placed within the skull
opening.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates a skull having multiple holes drilled to
form a skull opening and remove a bone flap in order to access the
brain cavity, and an implantable bone support system of the present
application using clips to support the bone flap for replacement
within the skull opening following surgery.
[0013] FIG. 2 is a perspective view of one part of a two-part shelf
clip;
[0014] FIG. 3 is a schematic side view of the shelf clip of FIG. 2,
and showing a cut-away skull captured by the shelf clip, and the
bone flap supported on the clip;
[0015] FIG. 4 is a top view of the second part or locking cap of
the two-part shelf clip;
[0016] FIG. 5 is a perspective view of the locking cap of FIG.
4;
[0017] FIG. 6 is a perspective view showing the two parts of the
two-part shelf clip engaged together;
[0018] FIG. 7 is a schematic side view of the shelf clip of FIG. 6,
and showing a cut-away of the skull and bone flap engaged with the
shelf clip;
[0019] FIG. 8 is a front top perspective view of an alternate
embodiment of a shelf clip of the present application, where the
upper swivel portion of the clip is in the "closed" position for
capturing the bone flap or implant;
[0020] FIG. 9 is a front bottom perspective view of the closed
position shelf clip embodiment of FIG. 8;
[0021] FIG. 10 is a front view of the closed position shelf clip
embodiment of FIG. 8;
[0022] FIG. 11 is a front top perspective view of the shelf clip
embodiment of FIG. 8, where the upper swivel portion of the clip is
in the "open" position for receiving the bone flap or implant
within the skull opening;
[0023] FIG. 12 is a rear bottom perspective view of the open
position shelf clip embodiment of FIG. 8;
[0024] FIG. 13 is a rear view of the open position shelf clip
embodiment of FIG. 8;
[0025] FIG. 14 is an alternate embodiment of a shelf clip of the
present application, showing openings in the skull or ratcheting
leg;
[0026] FIG. 15 is another embodiment of the shelf clip along the
lines of FIG. 14, but with an alternate locking leg configuration
for protecting a large skull opening, for example drill holes;
[0027] FIGS. 16a and 16b are perspective views of another alternate
embodiment of the shelf clip of the present application, and
illustrate movement of the skull leg along the ratchet posts;
[0028] FIGS. 17a and 17b are perspective front views of the
embodiment of FIGS. 16, but with the leg engaged and moved along
the ratchet posts, and FIG. 17c is a perspective rear view of the
shelf clip in FIG. 17b;
[0029] FIG. 18a is an enlarged schematic view of the shelf clip of
FIG. 17c;
[0030] FIG. 18b is a further enlarged schematic view of the shelf
clip of FIG. 18a;
[0031] FIG. 19 is a perspective view of an insertion tool for
ratcheting the locking or ratcheting leg;
[0032] FIG. 20 is a side view of the insertion tool of FIG. 19;
[0033] FIG. 21 is a schematic perspective view of an alternate
insertion tool preparing to ratchet the locking leg of the shelf
clip into engaged position;
[0034] FIG. 22 is a schematic view of the tool and clip of FIG. 21
moved to a position for engagement with the bone flap;
[0035] FIGS. 23a and 23b illustrate schematic front and rear
perspectives of the shelf clip of FIG. 18b with the ratchet posts
removed; and
[0036] FIG. 23c is a front perspective view of the shelf clip of
FIG. 23a.
DETAILED DESCRIPTION
[0037] The implantable bone support system 12 illustrated in use in
FIG. 1 provides a simple, fast and easy device and method for
supporting the bone flap or implant B that eliminates the need for
the time consuming use of screws, so surgical time to install the
bone support system is reduced. The shelf clips 10 of the present
application have a smooth and low profile which avoid adhesions
between the skull S and the scalp tissue T, and may be readily
removed in the event further surgery is required to remove the bone
flap B. In the descriptions of the embodiments which follow, where
components have the same name, they may be referred to using the
same reference character, or using the same reference character but
with a prime designation.
[0038] In the illustrated embodiment of FIGS. 2 to 7, a two-part,
fixed height shelf clip 10 is provided. The clip 10 includes a
lower body portion 14 having a base 16 with opposing legs 18, 20
extending from the base, and also includes an upper body portion
22. A central post 28 extends between the lower and upper body
portions 14, 22. The upper and lower body portions include 3 legs;
2 of which are spaced apart from one another by the fixed height
base 16 and extend in a direction away from the base to engage the
external ES and internal surfaces IS of the skull S, called the
skull legs, 18, 20. The third leg, the bone flap support leg 24,
extends in a direction opposite from the skull legs 18, 20, such
that when the bone flap B is repositioned within the skull opening
O on a shelf 30, it is supported on the bone flap support leg. The
central post 28 is eventually located within the kerf gap K and can
act as a compression wedge for additional support and stabilization
and location.
[0039] The shelf clip 10 is supported surrounding a portion of the
perimeter P of the skull opening O using the illustrated clip 10
having central post 28 and 3 legs, with a fourth leg formed by a
locking cap 26 which is engaged with and secured to the clip 10 and
engages an external surface ES of the bone flap B to capture the
bone flap within or on shelf 30 created by the clips 10 upon
repositioning of the bone flap B within the skull opening O to
create the implantable bone support system. The clips 10 are held
in place by retention barbs 17 illustrated as positioned on each
leg, since each clip 10 must remain in position on the skull S
without manual assistance, screws or suturing when the bone flap B
is placed within the skull opening O during formation of the shelf
30.
[0040] The locking cap or leg 26 may be formed as a separate piece,
as shown in FIGS. 4 and 5, or as a one piece clip, not illustrated,
with a movable locking leg which pivots, flips on a hinge or
slides. Once the bone flap B is positioned within the skull opening
O the locking leg 26 is moved into locked or closed position to
capture the bone flap. In the two-piece embodiment of FIGS. 2-7,
the locking leg or cap 26 has a surface for mating engagement with
the shelf clip 10, and slides into closed position under either a
friction fit engagement or a defined positive engagement (e.g. a
designed slot/hook engagement) once the bone flap B is positioned
on the shelf 30. The central post 28 may be provided with a fixed
or adjustable height, as in FIGS. 8-13, so that variances in bone
skull S thickness (often ranging from 3 mm to 20 mm) may be readily
accommodated. No special surgical instrumentation or other tools
are required for installation of this clip embodiment.
[0041] In still another embodiment, shown in FIGS. 8 to 13, 3-4 of
the shelf clips 10' of the illustrated invention are first placed
on the skull S spaced around the perimeter P of the skull opening
O, similar to the configuration shown in FIG. 1. The clip 10'
enables temporary placement of a height or skull-thickness
adjustable clip that creates a shelf-like feature to place and
support the bone flap or implant B. In this 3 piece adjustable
height clip 10' embodiment, a lower body portion 14' is provided.
An upper body portion 22' is also included having an external
rotating portion 40 and a central portion 42 for engagement with
the central post 28' is provided. As shown, the lower body portion
14' includes opposing barbed legs 18' 24' extending from a base
supporting two central posts 28', where each post contains a
ratchet surface 44 or surfaces with angled teeth 46. In this
embodiment, the opposing barbed legs of the lower body portion 14'
form an H-shaped configuration. The teeth 46 of the central posts
28' are angled to enable locking engagement when angled ribs 48 on
the central portion 42 are engaged over the angled teeth 46 of the
central posts 28' to resist removal of the upper body portion 22'
of the clip 10' from the lower body portion 14'. The ability to
quickly and easily place and retain the clips in position on the
perimeter P of the skull opening O as a first step in use of the
device is unlike any prior art device or method currently used.
Prior art devices typically require multiple holding devices to
retain the fixation devices in position until the bone flap is
inserted. No such inconvenient positioning and holding of multiple
devices is provided with the present invention.
[0042] Following placement of the clips 10', pushing down the
central portion 42 of the upper body portion 22' onto the central
posts 28' enables height adjustment of each clip on the skull S.
The bone flap or implant B is then inserted into the opening O in
the skull S and supported on the legs 24' or shelf 30 extending
from the lower body portion 14'.
[0043] In the embodiment of FIGS. 8-13, once the bone flap or
implant B is inserted into the skull cavity opening O, the rotating
portion 40 of the clip 10' is rotated, approximately 180 degrees,
on the central portion 42 of the clip, engaged and supported within
a rail or mating tongue and groove structure 50 provided between
the central portion 42 and rotating portion 40 of the upper body
portion of the clip. The rotating external portion 40 of the clip
10' includes a rounded and extending boss portion 52 which extends
over the bone flap B to "sandwich" the bone flap between the bone
flap support leg 24' of the clip and the rotated boss portion 52 of
the clip, to thereby support and capture the bone flap B within the
skull opening O. It is noted that an opening 54 is provided in the
boss portion 52 of the clip 10' in the event additional fixation
using conventional screws through the opening 54 is desired.
[0044] In a preferred form of this embodiment, the clip components
are stamped metal members which may be formed of numerous well
known and appropriate implantable metal materials, such as titanium
or surgical stainless steel. Alternatively, the device may be from
other appropriate prior art polymer materials such as PMMA or PEEK,
or of resorbable materials also known to those of ordinary skill in
the art. When used with resorbable material, the central portion of
the upper body portion of the clip acts as a filler or a wedge
within the kerf or gap K. When functioning as a wedge under the
application of compression loads on the clip of the present bone
support system 12, the resorbable material becomes especially
important, since it carries the load and promotes bone growth
across the kerf K. This is not the case with conventional screws
and plates, since the kerf is not filled, and the plates hold the
flap in a cantilever fashion. While prior art "sandwich" devices
may have a portion of the device within the kerf, they are not
designed to carry a compression load or to act to promote bone
growth across the kerf.
[0045] Still further embodiments of the shelf clip 10'', 10''',
10'''' are shown in the embodiments of FIGS. 16a to 18b, FIG. 14
and FIG. 15, respectively. The device includes several components
supported on a lower body portion 14, and an upper body portion 22.
The lower body portion formed on base 16 includes a skull leg 18''
and a bone flap support leg 24''. The upper body portion includes a
ratcheting leg 20'' and a locking leg 26''. A central post 28'',
taking the form of two posts each having a ratchet surface 44''
with ratchet teeth 46'', interconnects the upper and lower body
portions. The ratcheting leg 20'' is formed integral with a sleeve
60 which surrounds the central post 28'' and each of the ratchet
surfaces 44''. The sleeve 60 includes a mating tooth surface 62
which is positioned to engage the ratchet teeth 46'' of the central
post 28'' and resist removal of the ratcheting leg 20'' and sleeve
from the central post as the ratcheting leg is pushed toward the
lower body portion 14.
[0046] The figures depict the bone support system in various stages
of implantation, and are described below. As shown in FIGS. 16a and
16b, opposing barbed legs 18'', 20'' extend from base 16''. Locking
engagement of the teeth 46'' of the central post 28'' with the
tooth surface 62 as the ratcheting leg 20'' is engaged over the
angled teeth 46'' to resist removal of the upper body portion 22''
from the lower body portion 14''. FIG. 16b illustrates movement of
the ratcheting leg 20'' and sleeve 60 from the position shown in
FIG. 16a, toward the lower body portion 14''.
[0047] A locking leg 26'' also having a locking tooth surface 68,
engages with a stop surface 70 formed in the sleeve 60 of the
ratcheting leg 20'', resists removal of the locking leg 26'' from
the clip 10'', as shown in FIGS. 17a, 17b and 17c, and 23a, 23b and
23c. For optional additional strength in this embodiment, once the
ratcheting leg 20'' is fully engaged with the lower body portion
14'', tabs 66 extending from the central post 28'' are secured
within mating slots 64 in sleeve 60 of the ratcheting leg. In FIGS.
18a and 18b, the locking tooth surface 68 of the locking leg 26''
is shown engaged with the stop surface 70 extending out of the
plane of the ratcheting leg 20''. In an alternate design, teeth on
the locking leg 26'' could engage either the lower body portion
14'' or the central post 28.
[0048] Following the convenient and secure placement of the clips,
either on the skull S, or the bone flap B in another embodiment to
provide a convenient reversible device which is usable on either
bone edge surface, the mating bone flap or implant is then placed
into the opening O in the skull S, supported on the legs 24''
extending from each clip 10. In either position, the bone flap B is
positioned within the opening O formed in the skull S. Where the
clips 10 are secured on the edge of the skull rim, the clip serves
as a support shelf 30 with the support leg 24 underneath the bone
flap B, preventing it from passing into the skull cavity. The
locking leg 26'' is then engaged with the stop surface 70 on the
sleeve 60 of ratchet leg 20 and pushed down into the sleeve of clip
10, such that the upper body portion legs ratchet downward on the
ratchet surface 44'' of the central post 28. This engagement
enables proper height adjustment of the bone support system 12 on
the skull with the bone flap. Where the clips 10 are inverted and
secured on the edge of the bone flap B, the clip serves as a
support ledge on the top of the bone flap, with the ratcheting leg
20 extending across the gap K to the external surface ES of the
skull S to prevent the bone flap B from passing into the skull
cavity. Using this inverted position, the locking leg 26 is not
used, although a screw may eventually be used to secure the
ratcheting leg to the bone surface. It is possible that immediately
following the surgical procedure no screws would be used to allow
for potential swelling and optionally re-lifting of the bone flap.
Later, when desired, for example during in an outpatient procedure,
the surgeon might place screws, for example through openings 72 in
FIG. 14, 15 or 18a, to secure the clip 10.
[0049] To engage the locking leg 20'' in position, a pointed tool
or an insertion tool 75, illustrated in FIGS. 19 and 20, may used
to push down or ratchet down the teeth 68 of the locking leg 26 and
ratchet leg 20 into a secure position, such that the clip 10 is
then engaged both on the inside surface of the skull S or bone flap
B and on an external surface ES of the skull or bone flap. In the
illustrated embodiment, the locking leg locks into the sleeve of
the ratchet leg mounted on the central post. As previously
mentioned, it should be understood that in an alternate design the
locking leg could also be locked into engagement with the central
post. Again, the barbs 17 ensure fixation so that the clip resists
removal. However, in the event conventional fixation is desired,
screw holes 72 may be provided in the locking and ratchet legs 26,
20 to enable the use of screws to further secure the legs in
position.
[0050] Following locking engagement of the clip 10'' with the bone
flap and skull, the central post 28'' of the lower body portion
14'' is/are bent and/or cut to the proper height, to avoid
interference once tissue T is resecured over the bone support
system 12, skull S and bone flap B. In an alternate embodiment,
shown in FIGS. 21a and 21b, after the bone flap B is placed on the
shelf 30, a hand held tube-like member 76 is used to place the
locking leg 26'' and push or ratchet the locking leg into place,
engaged within the bone support system 12. The hand held tube-like
tool 76 is also used to break off the central post 28'' that
protrudes above the legs 20'', 26'' toward the scalp tissue T. This
is accomplished by simply bending the hand held disposable tool 76
backwards once the locking leg 26'' is in the desired position.
[0051] Once the central post 28'' is/are trimmed to the desired
profile, whether by hand or using a tool, the bone support system
12 of FIGS. 23a, 23b and 23c is secured at the desired adjusted
bone thickness or height appropriate for the circumstance,
surrounding bone flap or implant and skull bone along the lines
schematically illustrated in FIG. 7. It should be noted that the
size of the present clip device is sufficiently small that the
central post which fill the gap K intermediate the bone flap B and
the skull opening, are essentially similar in size to the thickness
of the saw blades used to remove the bone flap, or typically 1 mm
up to 3 mm in thickness. The thickness of the central post serves
to substantially fill the curve or gap or kerf K and thereby carry
the load in case an external force is applied which otherwise would
press the bone flap into the opening.
[0052] The use of the present device to provide a fast and simple
technique for easily securing the bone flap B within the skull
cavity opening O provides many advantages. The shelf clip 10 device
has a very low profile at the surface of the skull S and bone flap
B. The height of the clip 10', 10'' is adjustable for each
individual situation. The shelf clip has equal or greater strength
than comparable plates and screws. Reduced product inventory is
required due to the adjustability of the height, and that
essentially one size fits all and multiple plates and screw sizes
are not required. The one size fits all ability of the present clip
eliminates not only the multiple sizes and shapes of the plates and
screws being replaced, but may also provide a clip device which is
curved to mate with skull curvature. Less inventory generally
results in less surgical preparation time due to less sterilization
and less product to stock. Additionally, since one size fits all,
there is less product lost during surgery in the event that an
improper size is initially selected and must be discarded, as is
the case with other fixation devices. Also, one size reduces the
number of decisions which must be made at the end of surgery about
the proper clip size.
[0053] Additional improvements making use of the embodiment of
FIGS. 19 to 20 would include the use of a cartridge to be used with
the insertion tool. The cartridge would be filled, for example,
with multiple pre-loaded shelf clips, 4 for example, which could be
easily mounted at the desired locations on the edge of the bone
flap or skull cavity rim, after which the insertion tool would be
used, also having the pre-loaded locking leg component of the clip
for one handed pushing or ratcheting down of each locking leg into
the positioned clip for ease of use. It is believed that the
present shelf or ledge clip could likewise be used for temporary
reconfiguration of bone fragments, for example, to reconnect bone
fragments separated during a traumatic event, and requiring
multiple reconnections, essentially to reform a patchwork of bone
fragments either with or without implant materials or implants of
PMMA, PEEK, titanium or ceramic for reconstruction into a single
unit, which is otherwise a very difficult item to hold together
during a surgical procedure.
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